It’s every bro’s favorite question, but the answer is of tremendous importance to everyone alive. Everyone’s body, not just bodybuilders or strength athletes, needs protein to grow and sustain bones, muscles, cartilage, skin, blood and more.

Why The Confusion?

Just about anyone who’s been inside a weight room a few times has heard someone bring up the necessity of consuming protein to make sure you fuel the muscle growth you are stimulating. The inevitable followup part of that discussion is, how much?!

Protein supplement manufacturers and distributors have successfully perpetuated this idea that 1g/lb of bodyweight is the minimum amount of protein one needs to foster growth but that higher amounts can further increase muscle growth. The 1g/lb of bodyweight rule of thumb is supported by Arnold Schwarzenegger so it’s no wonder why it has become so ubiquitous, and I’ll admit I held this belief for over a decade.

There are literally thousands of articles addressing this topic, so for the sake of those trying to find reliable information quickly I’ll try to keep this article brief, but informative.

The Science

I’ll go ahead and tell you that there isn’t a magical number. Not only do sedentary individuals have different protein requirements than athletes, but the actual rate of protein synthesis your body can sustain fluctuates based on your age, your day-to-day activities, your diet, any particular hormone-enhancing “supplements” you may be taking, etc.

However, scientists have done some pretty solid research on this topic, and while you won’t find this information on the websites of those whose income relies largely on the sales of protein supplements, you will likely find similar recommendations between the pages of exercise science textbooks.

So back in 1992 two different experiments were conducted to test the affects of varying levels of protein on one’s ability to synthesize that protein (i.e. use it for growth). The first was conducted to test how much protein was needed during the early stages of intense bodybuilding training. P.W. Lemon and M.A. Tarnopolsky showed that athletes training 1.5 hours per day 6 days a week saw no difference in muscle mass or strength gains between individuals consuming 1.2g/lb or just 0.61g/lb. They only tested this for 1 month’s worth of training and encouraged a further study to observe if differences would occur over a longer period of time.

That same year, M.A. Tarnopolsky tried to do just that. In this experiment, 3 levels of protein intake were measured on 2 groups of people: sedentary adults and strength athletes. The results showed that for strength athletes, a high protein diet equivalent to 1.08g/lb bodyweight did NOT generate any increase in protein synthesis compared to a moderate protein intake of 0.63g/lb. For sedentary adults, the moderate protein intake proved too high, and a protein intake level of .4g/lb showed to be sufficient at maintaining normal cellular activity.

Both of these experiments show that persons who are routinely resistance training or performing other physically demanding activites are indeed in need of higher protein amounts in their diet, but more protein does not equal more muscle. Therefore, these popular workout programs recommending 1.5 to even 3 grams of protein per pound of bodyweight are simply misguided in their strategy. High levels of protein are toxic and can easily result in kidney stones, especially if not flushed from the body with adequate hydration.

Our bodies can only synthesize so much protein each day, and while diet, resistance training and other factors can boost our rate of protein synthesis, it will eventually plateau. Trying to consume protein beyond this point just triggers our bodies to convert the excess protein into body fat for later use.

My Test

To test this myself, I recently tried a popular workout program that suggests consuming 1.5g/lb of bodyweight. I cut that amount in half to 0.75g/lb and moved the other .75g over to my carbohydrate intake (since it was the same amount of calories either way). I dropped 8lbs of body fat in 3 weeks and 3 days without losing a single gram of muscle mass. So not only did I cut the protein in half, but I did so in a caloric deficit and still maintained every bit of my muscle mass, which is something many are terrified of trying.

Currently, I’m testing a similar protein intake with the intent of increasing lean mass rather than cutting body fat, so I’ll be reporting my results with that later this year. The strategy in this case will be to supply my body with all of its energy needs via carbohydrates and fat (it’s preferred energy sources) so that every bit of protein I consume can go towards my maximum protein synthesis capacity.

The Conclusion

Again, daily activities, age, diet and certain hormone boosting supplementation will affect your true optimal protein intake, but sedentary adults only need around 0.4g/lb of bodyweight, while strength athletes can consume up to 0.63g/lb and expect noticeable results, but beyond this amount, any increases to protein synthesis will be marginal at best.

For those skimming this article, that’s:

• Sedentary Adults – 0.4g/lb 
• Strength Athletes – 0.63g/lb

If you’re really desperate for a magical number tailored to you specifically, see a nutritionist or registered dietician. They’ll have the equipment and knowledge necessary to tell you exactly how much protein and other nutrients you should be consuming each day.